阀秆升降不灵活的原因是填料里有油，高温油被烧焦而使填料收缩，油变成积炭刮伤阀秆。
参考答案：错
—Why didn’t you buy that pair of trousers?
—I disliked its _________.Besides,the colour didn’t suit me.
A．pattern
B．manner
C．size
D．standard
以下几种常见的病理步态哪一种是正确的()
A．减痛步常见于足下垂
B．回旋步常见于偏瘫病人足内翻
C．剪刀步常见于小儿麻痹后遗症
D．斜肩步常见于股四头肌瘫痪
E．前冲步常见于小脑性共济失调
